A linear body having flexibility has been put into practical use, for example, as a linear medical appliance inserted in a vessel in a body. Specifically, a guide wire or a catheter inserted in a vessel in a body such as a blood vessel, a ureter, a bronchus, an alimentary canal, or a lymph vessel, a wire having an embolic coil attached at a tip end for embolizing an aneurysm, or the like has been known.
Applications of such a linear body include, for example, a surgical operation for embolizing a cerebral aneurysm with a platinum coil or the like in order to avoid rupture of the cerebral aneurysm, which is a cause of subarachnoid hemorrhage. In this case, a wire provided with an embolic coil at a tip end, that can be detached by applying electricity or water pressure, is used to fill the cerebral aneurysm with the coil. In order to fill the aneurysm with the coil, a catheter for guiding a wire provided with the coil to the cerebral aneurysm should be brought to the cerebral aneurysm.
Here, as the catheter is made of a soft material, the catheter cannot reach the cerebral aneurysm by itself. Accordingly, the catheter is guided to the cerebral aneurysm by using an extremely thin wire called a guide wire. Specifically, the guide wire representing a linear body is inserted in a hole in the center of the catheter, and in this state, the catheter in which the guide wire has been inserted is inserted in a human body. Then, the catheter is guided to the cerebral aneurysm by operating the guide wire from the outside of the human body. When the catheter is guided to the cerebral aneurysm by using the guide wire, the guide wire is subsequently pulled out of the catheter. Thereafter, the wire provided with the coil at the tip end is inserted in the hole of the catheter.
In a surgical operation for embolizing the cerebral aneurysm, in order to densely fill the cerebral aneurysm of which blood vessel wall has become thin with a plurality of coils, the wire provided with the coil should be operated with extreme care. On the other hand, an operation of the wire requires skills as it is performed from the outside of the human body. As such, though a surgical operation for embolization above is advantageous in that less burden is imposed on a human body than in a conventional surgical operation, the operation of the wire provided with the coil is highly difficult and the surgical operation has been difficult.
In order to solve such a problem, for example, a system using main and sub actuators is available as shown in Japanese Patent Laying-Open No. 2000-42116 (Patent Document 1). According to this system, in order for an operator to delicately operate a linear body, movement of a main actuator operated by the operator is carried out on a different scale by a sub actuator directly driving the wire.
Patent Document 1: Japanese Patent Laying-Open No. 2000-42116